This invention relates to a seat combination switch having a plurality of switch portions for operating a power seat.
One example of seats mounted on a vehicle is a so-called power seat whose position can be automatically adjusted by an electric motor. Generally, a switch for operating this electric motor is mounted on a side surface of a seat cushion portion (seat portion). Japanese Utility Model Unexamined Publication No. Hei. 3-20823 discloses one example of such seat switch having a pair of switch operating portions (key tops) mounted on an upper surface thereof, and this seat switch will be described with reference to FIGS. 18 and 19.
FIG. 18 is a perspective view of a seat having the conventional seat switch mounted thereon, and FIG. 19 is a perspective view of the seat switch having the pair of key tops. The pair of key tops 5a and 5b are mounted on and project from an upper surface of the seat switch 3 mounted on a side surface la of the power seat (hereinafter referred to as "seat") 1. Each of the key tops 5a and 5b is tiltable in four directions, and for example the key top 5a can operate a forward-backward slide mechanism and a front lifter mechanism while the other key top 5b can operate a reclining mechanism and a rear lifter mechanism.
The seat switch 3 comprises a switch body 7 having the pair of key tops 5a and 5b mounted thereon in a projected manner, and a box-like switch cover 9 of a synthetic resin which covers the switch body 7, and is fixedly secured thereto by screws 11. A pair of holes 13a and 13b are formed through an upper wall of the switch cover 9, and the key tops 5a and 5b extend respectively through these through holes 13a and 13b, and project beyond the upper surface of the switch cover 9 so that the key tops 5a and 5b can be tilted.
Another conventional seat switch, in which three kinds of switches can be selectively operated by a single operating knob, is disclosed, for example, in Japanese Utility Model Unexamined Publication No. Hei. 3-10443. FIG. 20 is a cross-sectional view of the conventional seat switch capable of effecting the selective operation by means of the single knob.
A first moving member 17, a second moving member 19 and a third moving member 21 are mounted on a switch casing 15. The first or central moving member 17 is movable forward and backward (that is, left and right in the drawing), and the right and left moving members are movable upward and downward (that is, upward and downward in the drawing). A switch is mounted at a lower end of the respective moving members 17, 19 and 21, and is operated in accordance with the movement of the corresponding moving member. Each of the moving members is driven only in accordance with the movement of the single operating knob 22 (mounted on the upper portions of the moving members) in a corresponding, specified direction.
In the operation of the seat switch 23 of this construction, when the operating knob 22 is slid forward and backward, the first moving member 17 is moved forward and backward (at this time, the second and third moving members 19 and 21 will not be moved), so that the first switch 27 is switched, thereby moving the seat 1 forward and backward.
When the front portion of the operating knob 22 is pivotally moved upward and downward, the second moving member 19 is moved upward and downward (at this time, the first and third moving members 17 and 21 will not be moved), so that the second switch (not shown) is switched, thereby moving the front portion of the seat upward and downward.
When the rear portion of the operating knob 22 is pivotally moved upward and downward, the third moving member 21 is moved upward and downward (at this time, the first and second moving members 17 and 19 will not be moved), so that the third switch (not shown) is switched, thereby moving the rear portion of the seat 1 upward and downward.
When the whole of the operating knob 22 is moved upward and downward, the second and third moving members 19 and 21 are both moved upward and downward (at this time, the first moving member 17 will not be moved), so that the second and third switches (not shown) are switched at the same time, thereby moving the whole of the seat 1 upward and downward.
In the conventional seat switch 3 shown in FIG. 19, the key tops 5a and 5b project from the upper surface, thus enabling the easy operation of the seat. However, during the operation of the vehicle, the seat switch is required to be operated without resort to the eyes, and besides it is rather difficult to suitably control the operating force, and therefore there has been encountered a problem that the key tops 5a and 5b tend to be tilted by an excessive force, and therefore are subjected to premature damage or breakage. And besides, since the seat switch 3 projects from that side surface of the seat 1 facing a door of the vehicle, the foot of the passenger or driver or a luggage often strikes against the seat switch when the passenger gets on and off the vehicle, so that an impact is applied to the seat switch, which has resulted in a problem that the seat switch is damaged. Furthermore, in the seat switch 3, the through holes 13a and 13b are formed through the upper wall of the switch cover 9, and therefore rain water or drinking water taken by the passenger is liable to intrude into the seat switch through these through holes, so that a malfunction such as short circuiting often occurs.
The conventional seat switch 23 of FIG. 20, though excellent in operability, is also projected from the side surface of the seat, and therefore is liable to be subjected to an impact when getting on and off the vehicle, and hence is liable to be damaged, and may often be operated accidentally. Further, in this seat switch 23, any particular means for preventing the intrusion of rain water or the like is not provided as in the above conventional seat switch, and this leads to the possibility of short circuiting due to the intrusion of the rain water or the like. If a rubber contact member, which is excellent in waterproof and dust prevention properties, is applied to the seat switch 23 of such a construction, the construction becomes complicated, and advantages achieved by the rubber contact member, such as the durability, a reduced number of component parts, and a lightweight and simple construction, are not fully attained.